This research examines the validity of the normative embourgeoisement perspective—the familiar notion that manual workers are becoming middle class in their cognitive orientations. Data are used from ten national surveys between 1956 and 1976 to examine changes in middle class identification among manual and nonmanual workers. Contrary to some earlier research which examined only two time periods, the results indicate that middle class identification among manual workers has increased over time at a faster rate than among nonmanual workers. Thus, there is greater similarity between manuals and nonmanuals in their middle class identification. Contrary to the arguments of normative embourgeoisement, however, the socioeconomic status (i.e., education, income, and occupational prestige) gains of manuals relative to nonmanuals do not account for this increased similarity. The research shows the need to apply longitudinal tests to dynamic theoretical perspectives, and the potential problems involved in such tests when only two periods are examined.